/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.mpp.execution.operator.schema;

import com.google.common.util.concurrent.ListenableFuture;
import org.apache.iotdb.commons.exception.IllegalPathException;
import org.apache.iotdb.commons.path.PartialPath;
import org.apache.iotdb.db.mpp.common.header.ColumnHeader;
import org.apache.iotdb.db.mpp.common.header.ColumnHeaderConstant;
import org.apache.iotdb.db.mpp.execution.operator.Operator;
import org.apache.iotdb.db.mpp.execution.operator.OperatorContext;
import org.apache.iotdb.db.mpp.execution.operator.process.ProcessOperator;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.read.common.block.TsBlock;
import org.apache.iotdb.tsfile.read.common.block.TsBlockBuilder;
import org.apache.iotdb.tsfile.utils.Binary;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.stream.Collectors;

import static java.util.Objects.requireNonNull;

public class NodePathsConvertOperator implements ProcessOperator {

    private static final Logger LOGGER = LoggerFactory.getLogger(NodePathsConvertOperator.class);

    private final OperatorContext operatorContext;
    private final Operator child;

    private final List<TSDataType> outputDataTypes;

    public NodePathsConvertOperator(OperatorContext operatorContext, Operator child) {
        this.operatorContext = requireNonNull(operatorContext, "operatorContext is null");
        this.child = requireNonNull(child, "child operator is null");
        this.outputDataTypes =
                ColumnHeaderConstant.showChildNodesColumnHeaders.stream()
                        .map(ColumnHeader::getColumnType)
                        .collect(Collectors.toList());
    }

    @Override
    public OperatorContext getOperatorContext() {
        return operatorContext;
    }

    @Override
    public ListenableFuture<?> isBlocked() {
        return child.isBlocked();
    }

    @Override
    public TsBlock next() {
        TsBlock block = child.nextWithTimer();
        if (block == null || block.isEmpty()) {
            return null;
        }
        TsBlockBuilder tsBlockBuilder = new TsBlockBuilder(outputDataTypes);

        for (int i = 0; i < block.getPositionCount(); i++) {
            String path = block.getColumn(0).getBinary(i).toString();
            PartialPath partialPath;
            try {
                partialPath = new PartialPath(path);
            } catch (IllegalPathException e) {
                LOGGER.warn("Failed to convert node path to PartialPath {}", path);
                continue;
            }
            tsBlockBuilder.getTimeColumnBuilder().writeLong(0L);
            tsBlockBuilder.getColumnBuilder(0).writeBinary(new Binary(partialPath.getTailNode()));
            tsBlockBuilder.declarePosition();
        }

        return tsBlockBuilder.build();
    }

    @Override
    public boolean hasNext() {
        return child.hasNextWithTimer();
    }

    @Override
    public void close() throws Exception {
        child.close();
    }

    @Override
    public boolean isFinished() {
        return child.isFinished();
    }

    @Override
    public long calculateMaxPeekMemory() {
        return child.calculateMaxReturnSize() + child.calculateMaxPeekMemory();
    }

    @Override
    public long calculateMaxReturnSize() {
        return child.calculateMaxReturnSize();
    }

    @Override
    public long calculateRetainedSizeAfterCallingNext() {
        return child.calculateRetainedSizeAfterCallingNext();
    }
}
